The present invention relates to a rack for stacking metal sections.
Metal sections are in general subjected, during a production cycle, to various stages of processing, as for example heat treatments to improve their mechanical properties. To this end, the sections are stacked together so as to be capable of being transported to a processing station (a furnace in the case in question).
A known solution, described in document EP-A-0585507 comprises arranging the sections on an open rack. The rack is constituted by a plurality of mutually facing vertical frames, each of which is provided with a number of equidistant cross-pieces; the sections are supported horizontally on the corresponding cross-pieces of the frames.
The sections must have a maximum vertical dimension less than the distance between two adjoining cross-pieces of each frame. In order to permit the use of sections of larger dimensions, the above-mentioned document describes a structure in which each cross-piece is hinged on the upright; in this way, the cross-piece may be rotated about the upright to adopt a rest position in which it extends towards the adjacent frame. Alternatively, the said document also proposes the use of cross-pieces that can be removed from the upright.
A disadvantage of the known structure described above resides in the fact that each operation to adjust the rack is somewhat complex and laborious, in that it is necessary to operate individually on each cross-piece (to be rotated or to be removed). Furthermore, in the event that the cross-pieces are hinged on the upright, the cross-pieces are not secured reliably in the rest position, so that they can easily become loose during the transportation of the rack (unloading). On the other hand, the solution using the removable cross-pieces includes cross-piece installation and dismantling operations which require a very large amount of time.
The object of the present invention is to overcome the above-mentioned drawbacks. In order to achieve this object, a rack is proposed for stacking metal sections as indicated in the first claim.
In brief, the present invention provides a rack for stacking metal sections, comprising a plurality of mutually facing frames, each frame comprising at least one upright and a plurality of cross-pieces extending from the at least one upright to define support surfaces for the sections, at least one further frame associated with each frame, each further frame comprising at least one further upright and a plurality of further cross-pieces extending from the at least one further upright and being movable between a rest position in which each further cross-piece is disposed at the same height as a corresponding cross-piece and a working position in which each further cross-piece is disposed at a different height to define further support surfaces for the sections, and means for securing the further frames in the rest position or in the working position.
Furthermore, the present invention also proposes a corresponding method for adjusting the rack.